import { INCREMENTCOUNT,DECREMENTCOUNT } from "../constant/countConst";

//定义reducer的初始值
const init={
    count:0
}
export default function countReducer(prevStata=init,action){
    console.log('reducer调用了');

    //接受action对象的type和data
    const {
        type,
        data
    }=action

    switch (type){
        case INCREMENTCOUNT:
        return {
            ...init, count:prevStata.count+data
        };

        case DECREMENTCOUNT:
            return {
                ...init, count:prevStata.count-data
            }
    }
    return prevStata;
}